Virginia Tech Weed Identification Guide

Black Nightshade: Solanum nigrum

Weed Description:   An annual or short-lived perennial ranging from 1 1/2 to 3 1/3 feet in height.   Black nightshade is primarily a weed of agronomic crops, forages, and gardens that is found along the West Coast of the United States only.

Seedling:  Cotyledons are covered with short hairs along the margins, midribs evident on lower surface, and petioles are also covered with hairs.   Stems below the cotyledons (hypocotyls) are hairy and green in color.

Roots:  Fibrous with shallow taproot.

Leaves:  Alternate, petioled, egg-shaped in outline, margins variable either without teeth or shallowly round-toothed.  Leaf pubescence is highly variable.

Stems:  Slender and becoming woody with age, may be round, ridged, ridged with small teeth, with or without hairs.

Flowers:  Star-shaped, in umbel-like clusters, 4-9 per cluster, white.

Fruit:  A berry, round, 5-10 mm in diameter, green early, turning black or dark green at maturity.  Berries do not contain sclerotic granules.

Identifying Characteristics:  Nightshade with berries that do not contain sclerotic granules, as those in Eastern Black Nightshade (Solanum ptycanthum) do. This species is not found in the eastern United States.